Ann, they are beautiful and do stand out well from the white pebbles. Your detail in each flower is excellent. And the purples and greens are outstanding, too!
"Where there is perhaps a province in which the photograph can tell us nothing more than what we see with our own eyes, there is another in which it proves to us how little our eyes permit us to see." ~Dorothea Lange
Nice contrast. I would suggest trying something with it tho. The leaves at the top are a little distracting, can you crop those a bit? And I would try adjusting the level a bit, darken the color of the flowers so they pop out even more.